1. Field of Invention
The present invention relates to a multiple variable valve lift apparatus and an engine including the same. More particularly, the present invention relates to a multiple variable valve lift apparatus that can implement a plurality of valve lift modes with a simple configuration, and an engine including the apparatus.
2. Description of Related Art
Internal combustion engines generate power by receiving and burning air and fuel in a combustion chamber. When air is sucked, an intake valve is operated by a camshaft and air is sucked into the combustion chamber while the intake valve is open. Further, an exhaust valve is operated by the camshaft and air is discharged from the combustion chamber while the exhaust valve is open.
The optimum operation of the intake valve/exhaust valve, however, depends on the RPM of the engine. That is, an appropriate time for a lift or valve opening/closing depends on the RPM of the engine. In order to implement an appropriate valve operation in accordance with the RPM of the engine, as described above, a VVL (Variable Valve Lift) apparatus having a plurality of shapes of cam operating valves or operating valves at different lifts in accordance with the RPM of an engine has been studied.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.